Magnetic information media are of course well known in the information storage and retrieval art and take many forms, typical of which are tape cartridges, hard and soft disks or diskettes, etc. In almost all cases, openings of one form or another are provided in the tape or disk container as incidents to certain functions in recording, playback, erasure, etc. Representative of these are the disclosures in U.S. Pat. Nos. 3,950,786 to Shapley and 4,460,930 to Takahashi. Nevertheless, those disclosures do not reveal a solution to the present problem, nor do they suggest, alone or together, an obvious way to adapt either patented means to the present diskette. The earlier patent refers to a tape and cartridge and thus is dimensionally as well as functionally inadequate. The later patent, although involving a disk, is totally structurally different and does not teach in applicant's direction.
According to the present invention, a simple and inexpensive erasure-prevention clip is provided as an element separate from the diskette and jacket; i.e., unlike some examples of the prior art, the clip is not an original portion broken off from and then replaced in or on the jacket. It is a feature of the invention that the clip may be easily manufactured of one-piece material, preferably of a suitable plastic such as polyvinylchloride impervious to light. The clip is a U-shaped member having a bight dimensioned to fit the notch, which is essentially "square" (except of course it is open at one side at the jacket edge in which it is formed) and the bight is therefore square. The legs of the member extend coextensively from the bight but are of greater area than that of the cross-section of the bight and thus overlie relatively broad notch-bordering areas at opposite sides or faces of the jacket, thus completely masking the notch from the entrance of light. It is significant that the legs are flexible and convergent away from the bight so as to increase the frictional grip thereof on the jacket.
It is a still further feature, in a modified form of clip, that the bight is itself made flexible in the form of a biased hinge, primarily by being folded on a line parallel to that edge of the disk jacket to which the clip is applied, thus making it easier to apply and remove the clip.
These and further features of the invention will become apparent as a preferred embodiment of the invention is disclosed in detail in the ensuing description and accompanying sheet of drawings.